This study is designed to demonstrate that losartan compared to placebo will reduce the number of NIDDM patients with nephropathy who experience doubling of serum creatinine, ESRD (dialysis, transplantation) or death. This study will also investigate the effect of losartan compared to placebo or cardiovascular morbidity and mortality, proteinuria and safety and tolerability. Tertiary parameters include quality of life and healthcare resource utilization.